Dynamo-electric machine



Oct. 20, 1925.

F. KRATZ ET AL.

pYNAuo ELECTRIC MACHINE Patented Oct. 20, 1925., UNITED STATES FRANZKRATZ ANDJILAX SCHAFER, OF STUTTGART, GERMANY, ASSIGNORS TO THE1,553,095 PATENT OFFICE. v

FIRM: ROBERT BOSCH AKTIENGESELLSOHAFT, OF STUTTGART, GERMANY.

DYNAMIC-ELECTRIC MACHINE.

Application filed August 11, 1921. Serial No. 491,554.

T all whom it may concern: I

Be it known that we, FRANZ KRATZ and Max SCHSFER, both German subjects,residing at Stuttgart, Germany, have invented certain new and usefulImprovements in Dynamo-Electric Machines, of which the following is aspecification.

The present invention relates to improvements in dynamo electricmachines of the type serving as a source of continuous current and alsosimultaneously as a magnetoelectric ignition device.

In the endeavor to simplify as far as possible the electric equipment ofmotor vehicles, efforts have already been made to combine the dynamoelectric machine for the electric lighting of the vehicle with themagneto ignition apparatus, into a single unit. In this case either theignition apparatus and the dynamo machine are arranged one above theother or the two machines lie axially one behind the other. In bothcases they have a common drive and their casings merge into one anotherin such a Way that the construction from the outside appears as acontinuous whole.

The improvements of this invention are directed to that ty e ofconstruction in which the two machines lie axially of one another. Theconstructions hitherto known of this type are of great length becausethe dynamo and the ignition apparatus are simply placed one behind theother, as they appear in their usual form, whilst of course a clutch ortransmission gear is also inserted between the two machines.

According to this invention a substantial shortening of the totallength. of such a con struction of dynamo and i ition apparatus isobtained by the rotor o the ignition apparatus being keyed on to anextension of the dynamo shaft.

If desired, the entire dynamo shaft may be supported only in endbearings, by whic arrangement the two bearings for the rotor, which arenecessary in an ignition apparatus arranged axially behind the dynamobut independently thereof, are saved and the apparatus shortened by thewidth oi at least two -bearings. Ina preferred embodiment of theinvention, illustrated in the accom- "rianying drawings, and later to bereferred Zto, however, the usual bearings for the dyna- .Il'lO shaft,are retained and one additional ,Q'T'Lbearing provided ,.{an nd bearingfor .the

extension of the dynamo shaft. By this arrangement, the construction isshortened by the width of at least one bearing over the ordinaryarrangement in which the ignition apparatus is arranged axially behindthe dynamo but independently thereof.

The foregoing advantages are obtained without sacrificing any desirablefeature of construction or of operation of the ignition apparatus. It isimmaterial, for example, whether the armature, the field magnets or acage formed of segmental flux guiding pieces be keyed on to the dynamoshaft to serve as the rotor of the ignition apparatus.

For automatic adjustment of the sparking point, a centrifugal governormay be arranged on the dynamo shaft between the dynamo armature and therotatably mounted rotor of the ignition apparatus, which governorcontrols the'conta'ct breaker or in certain cases also the distributor.

The invention is more particularly described with reference to theaccompanying drawings, in which,

Fig. 1 shows diagrammatically in plan View one form of our'invention,including an armature non-revoluble except by manual operation for thepurpose of adjusting the sparking point;

Fig. 2 shows diagrammatically in plan view another ,form of ourinvention, embodying an automatically operating means for adjusting thesparking point.

In both embodiments of the invention shown in Figs. 1 and 2, the dynamoelectric machine comprising the armature l and the field. 11, which ispreferably arranged to provide lighting current, is driven directly orindirectly from the crank shaft of the engine. The rotor of the ignitionapparatus or machine, in the present case a magneto arrangement 3, iskeyed on to an extension of the shaft 2 of the dynamo machine so as torotate with that shaft' The stationary armature 4 is mounted in thecasing 5 which encloses both machines.

In the embodiment of the invention illustrated in Fig. 1, the armature4: is adapted to be revolved throu h a certain angle by means of ahandle 6 %or the purpose of adjusting the sparking point. This handle isalso to be used for the same purpose in the construction shown in F ig.2, as there indicated.

The contact breaker, distributor and consparking point is effectedautomatically by means of a centrifugal governor.

In Fig. 2 the contact breaker and the distributor are showndiagrammatically at 8, driven by a shaft 8' disposed transversely to theextended dynamo shaft 2. The end of the shaft 8 adjacent the extensionof the dynamo shaft 2, has a worm gear 10 mounted thereon, in engagingrelation with a worm gear 11 mounted on the shaft 2, the gear 11constituting the driving-gear element.

The gear 11 is in the form of a sleeve surrounding the shaft 2 andsuitably mounted thereon, for example as by a spline, to partake ofrotary movement therewith and yet permit of an independent adjustingmovement of this gear 11 longitudinally of the shaft 2, under theinfluence of the centrifugal governor.

The gearing and the governor, as shown, are arranged upon the shaft 2,between the rotor 3 of the ignition apparatus and the bearing 9 of thedynamo machine 1, and hence the entire arrangement is one of extremecompactness.

The governor, as diagrammatically shown in Fig. 2, comprises a cu 7fixedly mounted upon the ri ht hand end (as the arts are viewed in Fi 2)of the gear-s eeve 11, a plate 12 fixedly mounted upon the shaft 2, andballs 13 freely positioned between the plate and cup and adapted to moveoutwardly from the shaft 2 under centrifugal action along the curvedinterior of the cup toward the rim thereof. Such movement of the ballsin an obvious manner imparts a longitudinal sliding movement of thegearsleeve 11 along the shaft 2 toward the left (as the parts are viewedin Fig. 2), under the resistance of the spring 14, the spring tending toreturn the parts to their initial position shown in Fig. 2.

The adjusting movement 'of the gearsleeve 11 under the operation of thegovernor, referred to above, obviously produces a partial rotation ofthe shaft 8' independently of its normal driven movement, which providesthe desired adjustment of the sparking point for different speeds ofrotation of the'driving shaft.

It will be understood, of course, that the driving means for thedistributor and contact breaker, illustrated in Fig. 2, may be employedwithout the governor or automatic adjusting means, the manual adjustmentof the armature 4 by the handle means shown more particularly in Fig. 1,then being relied on to adjust the sparking point. lVhen the governoradjustment is not employed, it. will also be understood that the gearsleeve 11 is keyed instead of splined on. the shaft 2 so as to rotatewith that shaft without any movement longitudinally of the shaft.

Various modifications may be made in the arrangement of the parts,including the cooperative arrangement of the armature, field magnets,contact breaker, condenser, distributer, etc. within the scope of ourinvention and realizing its advantageous features. For example, thearmature 4 of the ignition apparatus, instead of the magnet system 3 asshown, may be keyed to the dynamo shaft 2 to rotate therewith. In suchcase, the contact breaker, condenser and distributor may be disposed infixed positions, such as diagrammatically illustrated by the positionsof the contact breaker and distributor in Fig. 2, with conductors suchthat the, primary current is conveyed through a contact brush from thearmature of the ignition apparatus to the contact breaker, condenser anddistributor. Or, the contact breaker and condenser may be arranged torotate with the armature, in which arrangement they may beconnected'with the armature by fixed conductors, a feature preferred bysome in ractice. This feature of a fixed conductor tween the armatureand the contact breaker and condenser may also be retained when a fluxconductin cage serves as the rotor of the ma neto e ectr1c ignitionapparatus. In all 0 these variations the compact unitary assembly of thetwo devices, the dynamo electric machine and the ignition apparatus,illustrated in Figs. 1 and 2, may be utilized and the advantages of theinvention realized.

We declare that what we claim is 1. Combined direct current and hightenvsion ignition current generator, comprising,

in combination, a field structure and an armature for generating directcurrent of low tension, a shaft for the said armature, bearings for thesaid shaft, said shaft having an extension overhanging one of saidbearings, a magneto-electric ignition device provided with a rotor, therotor of said ignition device being mounted on the said extension of thearmature shaft- .so as to rotate therewith.

2. Combined direct current and high tension ignition current generator,comprising, in combination, a field structure and an armature forgenerating direct current of low tension, a shaft for the said armature,bearings for the said shaft, said shaft having an extension" overhangingone of the said bearings, a magneto-electric ignition device comprisinga normally stationary armature and a rotary magnetic field surroundingsaid armature and mounted on the said extension of the armature shaft soas to rotate therewith.

3. Combined direct current and high tension ignition current generator,comprising, in combination, .a field structure and an armature forgenerating direct current of low tension, a shaft for the said armature,bearings for the said shaft, said'shaft having an extension overhangingone of the said bearings, a magneto-electric ignition device comprisinga normally stationary armature and a rotary annular magnetic fieldsurrounding said armature andmounted on the said extension of thearmature shaft so as to rotate therewith.

at. Combined direct current and high ten sion ignition currentgenerator, comprising, in combination, a field structure and an armaturefor generating direct current of low tension, a shaft for the saidarmature, bearings for the said shaft, said shaft having an extensionoverhanging one of the said bearings, and a magneto-electric ignitiondevice comprising a normally stationary but rotatably adjustablearmature and an annular magnetic field surrounding said armature andmounted on the said extension of the armature shaft so as to rotatetherewith.

Combined direct current and high tension ignition current generator,comprising, in combination, a field structure and an armature forgenerating direct current of low tension, a shaft for the said armature,bearings for the said shaft, said shaft having an extension overhangingone of the said bearings, a iiiagneto-electric ignition device,comprising a rotor mounted on the said extension of the said armatureshaft so as to rotate therewith, a circuit controller, a driven shaftfor actuating said circuit controller and means for driving the saiddriven shaft from the said armature shaft of the direct currentgenerator.

6. Combined direct current and high tension ignition current generator,comprising, in combination, a .field structure and an armature forgenerating direct current of low tension, a shaft for the said armatureand bearings supporting said shaft, said shaft having an extensionbeyond said armature and overhanging one of said bearings, amagneto-electric ignition device compr1sing a rotor mounted on the saidextension of the said armature shaft so as to rotate therewith, acontact breaker and distribu 7. Combined direct current and high tensionignition current generator, comprising, in combination, a fieldstructure and an armature for generating direct current of U lowtension, a shaft for the said armature and bearings supporting saidshaft, said shaft having an extension beyond said armature andoverhanging one of said bearings, a magneto-electric ignition device,comprising a rotor mounted on the said extension of the said armatureshaft so as to rotate therewith, a contact breaker and distributor ing arotor mounted on the said extension I.

of the said armature shaft so as to rotate therewith, a contact breakerand distributor device, gearing members arranged on the said extensionof the armature shaft for driving the said contact breaker distributordevice, and centrifugal governor means arranged to receive its motionfrom the armature shaft for adjusting the position of the said contactbreaker and distributor device relative to the armature shaft for timingthe point of ignition.

9. Combined direct current and high tension ignition current generator,comprising, in combination, a field structure and an armature forgenerating direct current of low tension, a shaft for the said armaturehaving an extension beyond said armature, amagneto-electric ignitiondevice comprising a rotor mounted on the said extension of the saidarmature shaft so as to rotate therewith, a contact breaker anddistributor device,

gearing members arranged on the said exd contact breaker and distributordevice, and centrifugal governor means foradjusting the position of thesaid contact breaker and distributor device relative to the armatureshaft for timing the point of ignition; said centrifugal governor meansbeing arranged between the said armature and the said gearing members.

10. Combined direct current and high tension ignition current generator,comprising, in combination, a field structure and an armature forgenerating direct current of low tension, a shaft for the said armature,bearings for the said shaft, said shaft having an extension overhangingone of the said ttaiision of the armature shaft for driving the abearings, a magneto-electric ignition device comprising a rotor mountedon the said extension of the said armature shaft so as to rotatetherewith, a contact breaker and distributor device, gearing membersarranged on the said extension of the armature shaft for driving thesaid contact breaker and distributor device, and centrifugal governormeans for adjusting the position of the said contact breaker anddistributor device relative to the arn'iature shaft for timing the pointof ignition, said centrifugal governor means being arranged on theextension of the said armature shaft between the said bearing and thesaid rotor.

11. Combined direct current and high tension ignition current generator,comprising, in combination, a field structure and an armature forgenerating direct current of low tension, a shaft for the said armature,bearings for the said shaft, said shaft having an extension overhangingone of the said bearings, a magneto-electric ignition device comprisinga fixed armature and a magnetic field surrounding said armature andmounted on the said extension of the said armature shaft so as to rotatetherewith, a contact breaker and distributor device, gearing membersarranged on the said extension of the armature shaft for driving thesaid contact breaker and distributor device, and centrifugal governormeans for adjusting the position of the said contact breaker anddistributor device relative to the armature shaft for timing the pointof ignition, said centrifugal governor means being arranged on theextension of the said armature shaft between the said bearing and thesaid magnetic 'field.

12. Combined direct cnrr'ent and high tension ignition currentgenerator, comprising,

in combination, a field structure and an armature for generating directcurrent of low tension, a shaft for the said armature and bearingssupporting said shaft, said shaft having an extension beyond saidarmature and overhanging one of said bearings, a magneto-electricignition device comprlsmg a rotor mounted on the said extension of saidarmature shaft so as to rotate therewith, a circuit controllercomprising relative stationary and rosative parts, means for driving thesaid'rotative parts from the said armature shaft of the direct currentgenerator, and means for adjusting the position of certain of said partsrelative to the armature shaft for timing the point of ignition.

13. Combined direct current and high tension ignition current generatorcomprising, in combination, a field structure and an armature forgenerating direct current of low tension, a shaft for the said armature,bearings for said shaft, said shaft having an extension beyond saidarmature and overhanging one of said bearings a magnetoelectric ignitiondevice comprising a rotor mounted on said overhanging armatureshaft-extension, a contact breaker and distributor. device gearingmembers connected with said armature-shaft extension for driving saidcontact breaker and distributing FRANZ KBATZ. MAX soHAFER.

